This invention relates to broadening the utility of video cassette recorders and in particular to apparatus for enabling a user of a video cassette recorder connected to a cable television system employing a multi-channel converter box to achieve full programmer utility for the recorder.
The number of television receivers nationwide connected to cable television systems has grown dramatically in the last several years. Market surveys indicate approximately 13,000,000 homes are connected to a cable system, accounting for approximately a 20% market penetration. Forecasts indicate the market penetration will increase to at least 30% by 1982. Many of these cable television systems utilize a multi-channel converter for descrambling the very high frequency signals transmitted through the cable system. The converter has a preselected very high frequency output signal to which the television receiver is continuously set, e.g. channel 4. The converter also includes a preselector switch unit for permitting the user to select a single very high frequency signal from the entire range of signals transmitted by the cable system. The converter alters the selected very high frequency signal to the predetermined or preselected output signal for transmission to the television receiver. As used herein the term "very high frequency signals" includes the low and high band channels 2 through 13. Channels 2-13 are broadcast by the commercial television systems, whereas cable systems transmit both standard channels 2-13 and generally one or more of the special channels such as mid-band channels, A through I, subchannels A, C, or E, mid band channels A through I, or super band channels J through S.
In addition to the widespread use of cable television systems, the introduction of consumer video cassette recorders in the past few years has further increased the utility and overall user enjoyment of television. Video cassette recorders enable a person to video tape a television show for his own personal viewing pleasure. Essentially, the video cassette recorder is a convenience device for enabling a viewer to tape a television program that he may be unable to view when actually broadcast, either because the broadcast time is inconvenient or the viewer wishes to watch another program broadcast simultaneously with the program he wishes to record. A recent improvement in video cassette recorders enables a user to program the video cassette recorder to operate at preselected times during any consecutive seven days to record preselected programs appearing on any of the channels whether very high frequency or ultra high frequency, broadcast within the viewing area and received through the standard television antenna. However, video cassette recorders used in conjunction with cable television systems employing a multi-channel converter have not afforded the user full recorder utility.
For example, heretofore it has often been necessary for a user to obtain from a cable company a second converter box if the user wishes to record a first channel while viewing a second channel. In addition, the user must manually manipulate an external co-axial switch or switches to achieve the desired recording and viewing capabilities. The cable company's monthly charge to the user is increased by the foregoing arrangement since the cable company generally charges a monthly fee which increases with the number of converter boxes rented to the user.
Further, although programmable video cassette recorders are designed to automatically turn on and off and change channels at a predetermined time, on a given day within a seven day time span, the programmable video cassette recorder cannot override the preselector switch used in conjuntion with the multi-channel converter box. Thus, programmable video cassette recorders are not fully functional with cable systems employing multi-channel converter boxes. For example, the programmable video cassette recorder may be connected to the cable system through a manual switch whereby the recorder may select any regular or standard very high frequency channel, i.e. channels 2-13, transmitted through the cable system. However, if it is desired to record a special channel, i.e., a channel transmitted through the cable system that is not a standard very high frequency channel, such as the sub band, mid band or super band channels, it is necessary to connect the multi-channel converter to the video recorder. Once the input of the recorder is connected to the output of the converter, the channel changing feature of the programmable video cassette recorder is eliminated.
Although the present invention achieves particular utility with television receivers in association with video cassette recorders and cable systems of the type described, the invention may also be employed with television receivers connected to the described cable systems and utilizing remote control channel changers. In cable systems using the multi-channel converter, the television receiver tuner is set at one channel, which is the preselected converter output channel, e.g. channel 4. Thus, the remote channel changer presently cannot be employed to change channels transmitted through the multi-channel converter device.